Download or read book Flow Structure and Heat Transfer in an Impinging Jet CVD Reactor written by Nasir Memon and published by . This book was released on 2009 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed experimental study is undertaken to investigate the flow structure and heat transfer in an impinging jet Chemical Vapor Deposition (CVD) reactor at atmospheric pressure. It is critical to develop models that predict flow patterns in such a reactor to achieve uniform deposition across the substrate. Free convection can negatively affect the gas flow as cold inlet gas impinges on the heated substrate, leading to vortices and disturbances in the normal flow path. This experimental research will be used to understand the buoyancy-induced and momentum-driven flow structure encountered in an impinging jet CVD reactor. Investigations are conducted for various operational parameters such as substrate temperature and inlet velocity. In addition, different reactor geometries with varying inlet length and height between the substrate and inlet are included in the study. Experimental results obtained from the study provide information on the temperature distribution, heat transfer rates, and flow field. Such results validate the operation of the reactor at atmospheric pressure and provide valuable insight into future design of impinging jet CVD reactors.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1993 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impinging Stream Reactors written by A. Tamir and published by Elsevier. This book was released on 2014-06-28 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt: Impinging streams is a unique and multipurpose configuration of a two-phase suspension for intensifying transfer processes in heterogeneous systems, viz. gas-solid, gas-liquid, solid-liquid and liquid-liquid. The essence of the method lies in the collision which results from bringing two streams of a suspension flowing on the same axis in opposite directions. Following the impact of the streams, a relatively narrow zone is created, which offers excellent conditions for enhancing the heat and mass transfer between the phases in the suspension. The following processes are considered in the light of the method of impinging streams: drying of particles, solid-solid and gas-gas mixing, absorption and desorption of gases from liquids, combustion of gas and coal, calcination of phosphate, creation of emulsions, liquid-liquid extraction, dissolution of solids, ion exchange, dust collection and granulation as well as evaporative cooling of air. Additional aspects considered in the book are: power input in performing the above processes, heat and mass transfer coefficient and its correlation, mixing properties of impinging stream reactors, residence time of the particles in the reactors, scale-up of impinging-stream reactors with respect to pressure, drop, hold-up and mean residence time of the particles as well as the heat transfer. The aim of the book is to review the state-of-the-art in the field of impinging streams, to present results of theoretical and experimental research, and to stimulate research and industrial application of the method so that reactors employing impinging streams will become a common tool in chemical engineering and other disciplines of engineering. The major conclusion of this work is that almost any process in chemical engineering can be conducted by impinging streams, resulting in higher efficiency and less power input in comparison with conventional methods.
Download or read book A Numerical Investigation of the Axial Flow and Heat Transfer in a Barrel type Chemical Vapor Deposition CVD Reactor written by P. Shih and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Study of Flow and Heat Transfer in a Rotating Chemical Vapor Deposition Reactor written by Sun Wong and published by . This book was released on 2015 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental model was set up to study the rotating vertical impinging chemical vapor deposition reactor. Deposition occurs only when the system has enough thermal energy. Therefore, understanding the fluid characteristic and heat transfer of the system will provide a good basis to understand the full model. Growth rate and the uniformity of the film are the two most important factors in CVD process and it is depended on the flow and thermal characteristic within the system. Optimizing the operating parameters will result in better growth rate and uniformity. Operating parameters such as inflow velocity, inflow diameter and rotational speed are used to create different design simulations. Fluid velocities and various temperatures are recorded to see the effects of the different operating parameters. Velocities are recorded by using flow meter and hot wire anemometer. Temperatures are recorded by using various thermocouples and infrared thermometer. The result should provide a quantitative basis for the prediction, design and optimization of the system and process for design and fabrication of future CVD reactors. Further assessment of the system results will be discuss in detail such as effects of buoyancy and effects of rotation. The experimental study also coupled with a numerical study for further validation of both model. Comparisons between the two models are also presented.
Download or read book Numerical Analysis of an Impinging Jet Reactor for the CVD and Gas phase Nucleation of Titania written by and published by . This book was released on 1994 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Convective Heat Transfer and Flow Stability in Rotating Disk CVD Reactors written by and published by . This book was released on 1998 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The flow and heat transfer of NH3 and He have been studied in a rotating disk system with applications to chemical vapor deposition reactors. Influence of the important operating parameters were studied numerically over ranges of the primary dimensionless variables: (1) the spin Reynolds number, Re{sub {omega}}, (2) the disk mixed convection parameter, MCP{sub d}, and (3) a new parameter, the wall mixed convection parameter, MCP{sub w}. Inlet velocities were set to the corresponding infinite rotating disk asymptotic velocity. Results were obtained primarily for NH3. Results show that increasing Re{sub {omega}} from 314.5 to 3,145 increases the uniformity of the rotating disk heat flux and results in thinner thermal boundary layers at the disk surface. At Re{sub {omega}} = 314.5, increasing MCP{sub d} to 15 leads to significant departure from the infinite disk result with nonuniform disk heat fluxes and recirculating flow patterns. At Re{sub {omega}} = 3,145, the results are closer to the infinite disk for MCP{sub d} up to 15. For large values of MCP{sub w}, the flow recirculates and there is significant deviation from the infinite disk result. The influence of MCP{sub w} on flow stability is increased at larger MCP{sub d} and lower Re{sub {omega}}. The results show that because of variable transport properties, the flow of NH3 is less stable than that of He as MCP{sub d} is increased for MCP{sub w} = 0 and Re{sub {omega}} = 314.5.
Download or read book Multiphase Flow and Heat Transfer in Pebble Bed Reactor Core written by Shengyao Jiang and published by Springer Nature. This book was released on 2020-11-19 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces readers to gas flows and heat transfer in pebble bed reactor cores. It addresses fundamental issues regarding experimental and modeling methods for complex multiphase systems, as well as relevant applications and recent research advances. The numerical methods and experimental measurements/techniques used to solve pebble flows, as well as the content on radiation modeling for high-temperature pebble beds, will be of particular interest. This book is intended for a broad readership, including researchers and practitioners, and is sure to become a key reference resource for students and professionals alike.
Download or read book Heat Transfer and Fluid Flow in Nuclear Systems written by Henri Fenech and published by Pergamon. This book was released on 1981 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Comparative Study of Heat Transfer Enhancement Using Flow Impingement in Steam reforming Reactors written by Ian Kah Kidh Sit and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigates the enhancement of heat transfer in steam reformation reactors through the application of flow impingement in the catalyst bed. For steam reformation, it is known that the ability to convert hydrocarbons to hydrogen can be limited by heat transfer, mass transfer, and chemical kinetics. In this study, it is presented that flow impingement can be used to increase heat transfer in steam reformation through reduction of boundary layers and passive mixing. It is also presented that flow impingement could benefit mass transfer limitations through the same passive mixing, as well as increase chemical kinetics through enhanced heat transfer to reaction sites. As such, this study analyzes and compares the performance of a flow impinging catalyst, which consists of a novel structure, to that of a typical pelletized catalyst. The effects of flow impingement are experimentally investigated in conjunction with varied feedstock flow rates and reactor volumes. Their effects on reactor fuel conversion, temperature profile, heat transfer, characteristic time, and pressure drop are analyzed and studied. An empirical model for reactor performance was also developed and verified. The data collected by this study quantified the effects of flow impingement on steam reformation. Comparative test results found that utilization of flow impingement resulted in fuel conversion improvements of 1.1%-2.6%. In addition, experimental results also found improvements to the average heat transfer coefficients between reactors were 12%-21% when flow impingement was used. As such, it was determined that flow impingement could enhance heat transfer within the catalyst bed of a reactor, but this did not directly correlate with a similar improvement to fuel conversion. However, the application of flow impingement resulted in a 5%-15% decrease in characteristic conversion times, thus, confirming an overall improvement. It was concluded by this study that flow impingement could be an effective mechanism for enhancing heat transfer within steam reformation reactors; however, additional research on the efficacy of the employed flow schemes was recommended for enhancing overall performance of the process.
Download or read book Journal of Heat Transfer written by and published by . This book was released on 2002 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Influence of Convective Heat Transfer on Flow Stability in Rotating Disk Chemical Vapor Deposition Reactors written by William S. Winters and published by . This book was released on 1997 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Influence of Convective Heat Transfer on Flow Stability in Rotating Disk Chemical Vapor Deposition Reactors written by and published by . This book was released on 1997 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow and heat transfer of NH3 and He were studied in a rotating disk system with applications to chemical vapor deposition reactors. Flow field and disk heat flux were obtained over a range of operating conditions. Comparisons of disk convective heat transfer were made to infinite rotating disk results to appraise uniformity of transport to the disk. Important operating variables include disk spin rate, disk and enclosure temperatures, flow rate, composition, pressure, and gas mixture temperature at the reactor inlet. These variables were studied over ranges of the spin Reynolds number, Re[omega]; disk mixed convection parameter, MCP{sub w}; and wall mixed convection parameter, MCP{sub w}. Results obtained for NH3 show that increasing Re[omega] from 314.5 to 3145 increases the uniformity of rotating disk heat flux and results in thinner thermal boundary layers at the disk surface. At Re[omega]=314.5, increasing MCP{sub d} to 15 leads to significant departure from the infinite disk result with nonuniform disk heat fluxes and recirculating flow patterns; flow becomes increasingly complex at larger values of MCP{sub d}. At Re[omega] of 3145, results are closer to the infinite disk for MCP{sub d} up to 15. For large negative (hot walls) and positive (cold walls) values of MCP{sub w}, flow recirculates and there is significant deviation from the infinite disk result; nonuniformities occur at both values of Re[omega]. The influence of MCP{sub w} on flow stability is increased at larger MCP{sub d} and lower Re[omega]. To determine the influence of viscosity and thermal conductivity variation with temperature, calculations were made with He and NH3; He transport property variation is low relative to NH3. Results show that the flow of NH3 is less stable than that of He as MCP{sub d} is increased for MCP{sub w}=0 and Re[omega]=314.5. 16 refs., 15 figs., 1 tab.
Download or read book A Numerical and Experimental Investigation of the Fluid Dynamics and Heat Transfer in a Barrel type Chemical Vapor Deposition CVD Reactor microform written by Shih, Ping-Ho Samuel and published by Ann Arbor, Mich. : University Microfilms International. This book was released on 1988 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer in Horizontal and Vertical CVD Reactors written by Wilson Kuo Sun Chiu and published by . This book was released on 1997 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer and Fluid Flow in a Unique High Pressure Reactor written by Leon N. Vernon and published by . This book was released on 1956 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
